Dear Tom,
I’m always looking for hot weather, but this late in the year, I realize that it is a losing battle. Has Chicago ever reached 90 degrees in October?
—Mark S. Alsip
Dear Mark,
It has, but October 90s are few and far between. Since 1871, the city has logged just six October 90s and none since back-to-back highs of 92 and 91 on October 1-2, 1971. The shortening daylight and decreasing sun angle make it difficult to reach 90 degrees. Three of the October 90s occurred during the hot decade of the 1950s, 90 on October 4, 1951, 90 on October 2, 1953, and 91 on October 3, 1954. In 1963, the mercury reached 94 degrees on October 6, the highest reading ever recorded during the month. Since 2000, the city has booked 11 October days, where the mercury reached at least 85, the warmest day a high of 88 on October 3, 2018.